Will it damage this battery to hook in parallel with a 12 volt deep cycle battery?

On extended fishing trips in my Ice house, when my fish finder gets low on power, I would like to connect to the Ice House 12 volt power. Do I need to disconnect this battery, or can I just hook in parallel? Thanks.

What are the working tempratures for this battery?

The Cabela's Rechargeable 12-Volt Batteries do not have an absolute listed range of operating temperatures, though the optimum working temperature is 77 degrees F. Each sustained rise of 15 degrees above that temperature will cut battery life in half. Each decline of 18 degrees F below the average room temperature of 72 degrees F reduces the battery capacity by 10%.

How many items can be hooked to this battery depends entirely on how much amperage they draw. This battery has an 8 amp draw. Typical fishfinders draw anywhere from 250mA to 350 mA so adding another would reduce the time it needed between charges but still work, up to the capacity of the battery.

The Cabela's Rechargeable 12-Volt Battery, Item: IK-018049, can be used in multiple applications where a 12 volt DC battery is required. Replacing a 9 amp hour battery with an 8 amp hour battery would result in a slightly quicker battery discharge than before.

can this be charged with a standard battery charger

A standard battery charger should not be used with the Cabela's Rechargeable 12-Volt Batteries. Standard battery chargers output too many amps for this size of battery and can cause damage to the battery.

I have used a standard battery charger set a the lowest (2 amp) charging setting without problems. It's probably a good idea to use a better charger than what is included with the battery because the charger that is included is very basic and doesn't shut off after charging.

Yes. I've used it on my 36 lb thrust MinnKota with no problem. I carry a spare just to make sure I have plenty of power on long days on the water. I recharge them at the end of the day and it only takes a couple of hours to restore them to 100%.